Add a line api to PangoRenderer

This replaces and generalizes error underlines and
lets us draw squiggly strikethroughs and overlines.

4 files changed, 245 insertions, 246 deletions

diff --git a/pango/pango-renderer.c b/pango/pango-renderer.c
index 6f6f2c73..1a50eaa0 100644
--- a/pango/pango-renderer.c
+++ b/pango/pango-renderer.c
@@ -82,7 +82,9 @@ static void pango_renderer_default_draw_rectangle       (PangoRenderer    *rende
                                                          int               y,
                                                          int               width,
                                                          int               height);
-static void pango_renderer_default_draw_error_underline (PangoRenderer    *renderer,
+static void pango_renderer_default_draw_line            (PangoRenderer    *renderer,
+                                                         PangoRenderPart   part,
+                                                         PangoLineStyle    style,
                                                          int               x,
                                                          int               y,
                                                          int               width,
@@ -122,7 +124,7 @@ pango_renderer_class_init (PangoRendererClass *klass)
   klass->draw_glyphs = pango_renderer_default_draw_glyphs;
   klass->draw_glyph_item = pango_renderer_default_draw_glyph_item;
   klass->draw_rectangle = pango_renderer_default_draw_rectangle;
-  klass->draw_error_underline = pango_renderer_default_draw_error_underline;
+  klass->draw_line = pango_renderer_default_draw_line;
   klass->prepare_run = pango_renderer_default_prepare_run;
 
   gobject_class->finalize = pango_renderer_finalize;
@@ -220,38 +222,17 @@ draw_underline (PangoRenderer *renderer,
   state->underline = PANGO_LINE_STYLE_NONE;
   state->underline_position = PANGO_UNDERLINE_POSITION_NORMAL;
 
-  switch (underline)
-    {
-    case PANGO_LINE_STYLE_NONE:
-      break;
-    case PANGO_LINE_STYLE_DOUBLE:
-      pango_renderer_draw_rectangle (renderer,
-                                     PANGO_RENDER_PART_UNDERLINE,
-                                     rect->x,
-                                     rect->y + 2 * rect->height,
-                                     rect->width,
-                                     rect->height);
-      G_GNUC_FALLTHROUGH;
-    case PANGO_LINE_STYLE_SINGLE:
-    case PANGO_LINE_STYLE_DOTTED:
-    case PANGO_LINE_STYLE_DASHED:
-      pango_renderer_draw_rectangle (renderer,
-                                     PANGO_RENDER_PART_UNDERLINE,
-                                     rect->x,
-                                     rect->y,
-                                     rect->width,
-                                     rect->height);
-      break;
-    case PANGO_LINE_STYLE_WAVY:
-      pango_renderer_draw_error_underline (renderer,
-                                           rect->x,
-                                           rect->y,
-                                           rect->width,
-                                           3 * rect->height);
-      break;
-    default:
-      break;
-    }
+  if (underline == PANGO_LINE_STYLE_DOUBLE ||
+      underline == PANGO_LINE_STYLE_WAVY)
+    rect->height *= 3;
+
+  pango_renderer_draw_line (renderer,
+                            PANGO_RENDER_PART_UNDERLINE,
+                            underline,
+                            rect->x,
+                            rect->y,
+                            rect->width,
+                            rect->height);
 }
 
 static void
@@ -263,32 +244,20 @@ draw_overline (PangoRenderer *renderer,
 
   state->overline = PANGO_LINE_STYLE_NONE;
 
-  switch (overline)
+  if (overline == PANGO_LINE_STYLE_DOUBLE ||
+      overline == PANGO_LINE_STYLE_WAVY)
     {
-    case PANGO_LINE_STYLE_NONE:
-      break;
-    case PANGO_LINE_STYLE_DOUBLE:
-      pango_renderer_draw_rectangle (renderer,
-                                     PANGO_RENDER_PART_OVERLINE,
-                                     rect->x,
-                                     rect->y - 2 * rect->height,
-                                     rect->width,
-                                     rect->height);
-      G_GNUC_FALLTHROUGH;
-    case PANGO_LINE_STYLE_SINGLE:
-    case PANGO_LINE_STYLE_DOTTED:
-    case PANGO_LINE_STYLE_DASHED:
-    case PANGO_LINE_STYLE_WAVY:
-      pango_renderer_draw_rectangle (renderer,
-                                     PANGO_RENDER_PART_OVERLINE,
-                                     rect->x,
-                                     rect->y,
-                                     rect->width,
-                                     rect->height);
-      break;
-    default:
-      break;
+      rect->y -= 2 * rect->height;
+      rect->height *= 3;
     }
+
+  pango_renderer_draw_line (renderer,
+                            PANGO_RENDER_PART_OVERLINE,
+                            overline,
+                            rect->x,
+                            rect->y,
+                            rect->width,
+                            rect->height);
 }
 
 static void
@@ -302,33 +271,20 @@ draw_strikethrough (PangoRenderer *renderer,
       rect->y /= state->strikethrough_glyphs;
       rect->height /= state->strikethrough_glyphs;
 
-      switch (state->strikethrough)
+      if (state->strikethrough == PANGO_LINE_STYLE_DOUBLE ||
+          state->strikethrough == PANGO_LINE_STYLE_WAVY)
         {
-        case PANGO_LINE_STYLE_NONE:
-          break;
-        case PANGO_LINE_STYLE_DOUBLE:
-          pango_renderer_draw_rectangle (renderer,
-                                         PANGO_RENDER_PART_STRIKETHROUGH,
-                                         rect->x,
-                                         rect->y - rect->height,
-                                         rect->width,
-                                         rect->height);
-          rect->y += rect->height;
-          G_GNUC_FALLTHROUGH;
-        case PANGO_LINE_STYLE_SINGLE:
-        case PANGO_LINE_STYLE_DOTTED:
-        case PANGO_LINE_STYLE_DASHED:
-        case PANGO_LINE_STYLE_WAVY:
-          pango_renderer_draw_rectangle (renderer,
-                                         PANGO_RENDER_PART_STRIKETHROUGH,
-                                         rect->x,
-                                         rect->y,
-                                         rect->width,
-                                         rect->height);
-          break;
-        default:
-          break;
+          rect->y -= rect->height;
+          rect->height *= 3;
         }
+
+      pango_renderer_draw_line (renderer,
+                                PANGO_RENDER_PART_STRIKETHROUGH,
+                                state->strikethrough,
+                                rect->x,
+                                rect->y,
+                                rect->width,
+                                rect->height);
     }
 
   state->strikethrough = PANGO_LINE_STYLE_NONE;
@@ -403,33 +359,18 @@ add_underline (PangoRenderer    *renderer,
   new_rect.height = underline_thickness;
   new_rect.y = base_y;
 
-  switch (renderer->underline)
+  if (renderer->underline_position == PANGO_UNDERLINE_POSITION_UNDER)
+    new_rect.y += ink_rect->y + ink_rect->height + underline_thickness;
+  else
+    new_rect.y -= underline_position;
+
+  if (renderer->underline == state->underline &&
+      renderer->underline_position == state->underline_position)
     {
-    case PANGO_LINE_STYLE_NONE:
-      g_assert_not_reached ();
-      break;
-    case PANGO_LINE_STYLE_SINGLE:
-    case PANGO_LINE_STYLE_DASHED:
-    case PANGO_LINE_STYLE_DOTTED:
-      if (renderer->underline_position == PANGO_UNDERLINE_POSITION_UNDER)
-        {
-          new_rect.y += ink_rect->y + ink_rect->height + underline_thickness;
-          break;
-        }
-      G_GNUC_FALLTHROUGH;
-    case PANGO_LINE_STYLE_DOUBLE:
-    case PANGO_LINE_STYLE_WAVY:
-      new_rect.y -= underline_position;
-      if (state->underline == renderer->underline)
-        {
-          new_rect.y = MAX (current_rect->y, new_rect.y);
-          new_rect.height = MAX (current_rect->height, new_rect.height);
-          current_rect->y = new_rect.y;
-          current_rect->height = new_rect.height;
-        }
-      break;
-    default:
-      break;
+      new_rect.y = MAX (current_rect->y, new_rect.y);
+      new_rect.height = MAX (current_rect->height, new_rect.height);
+      current_rect->y = new_rect.y;
+      current_rect->height = new_rect.height;
     }
 
   if (renderer->underline == state->underline &&
@@ -984,39 +925,6 @@ pango_renderer_default_draw_rectangle (PangoRenderer  *renderer,
   draw_rectangle (renderer, renderer->matrix, part, x, y, width, height);
 }
 
-/**
- * pango_renderer_draw_error_underline:
- * @renderer: a `PangoRenderer`
- * @x: X coordinate of underline, in Pango units in user coordinate system
- * @y: Y coordinate of underline, in Pango units in user coordinate system
- * @width: width of underline, in Pango units in user coordinate system
- * @height: height of underline, in Pango units in user coordinate system
- *
- * Draw a squiggly line that approximately covers the given rectangle
- * in the style of an underline used to indicate a spelling error.
- *
- * The width of the underline is rounded to an integer number
- * of up/down segments and the resulting rectangle is centered
- * in the original rectangle.
- *
- * This should be called while @renderer is already active.
- * Use [method@Pango.Renderer.activate] to activate a renderer.
- *
- * Since: 1.8
- */
-void
-pango_renderer_draw_error_underline (PangoRenderer *renderer,
-                                     int            x,
-                                     int            y,
-                                     int            width,
-                                     int            height)
-{
-  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
-  g_return_if_fail (renderer->active_count > 0);
-
-  PANGO_RENDERER_GET_CLASS (renderer)->draw_error_underline (renderer, x, y, width, height);
-}
-
 /* We are drawing an error underline that looks like one of:
  *
  *  /\      /\      /\        /\      /\               -
@@ -1084,11 +992,12 @@ get_total_matrix (PangoMatrix       *total,
 }
 
 static void
-pango_renderer_default_draw_error_underline (PangoRenderer *renderer,
-                                             int            x,
-                                             int            y,
-                                             int            width,
-                                             int            height)
+draw_wavy_line (PangoRenderer   *renderer,
+                PangoRenderPart  part,
+                int              x,
+                int              y,
+                int              width,
+                int              height)
 {
   int square;
   int unit_width;
@@ -1121,7 +1030,7 @@ pango_renderer_default_draw_error_underline (PangoRenderer *renderer,
   i = (width_units - 1) / 2;
   while (TRUE)
     {
-      draw_rectangle (renderer, &total, PANGO_RENDER_PART_UNDERLINE, /* A */
+      draw_rectangle (renderer, &total, part, /* A */
                       0,                      0,
                       HEIGHT_SQUARES * 2 - 1, 1);
 
@@ -1129,7 +1038,7 @@ pango_renderer_default_draw_error_underline (PangoRenderer *renderer,
         break;
       i--;
 
-      draw_rectangle (renderer, &total, PANGO_RENDER_PART_UNDERLINE, /* B */
+      draw_rectangle (renderer, &total, part, /* B */
                       HEIGHT_SQUARES * 2 - 2, - (HEIGHT_SQUARES * 2 - 3),
                       1,                      HEIGHT_SQUARES * 2 - 3);
 
@@ -1138,13 +1047,78 @@ pango_renderer_default_draw_error_underline (PangoRenderer *renderer,
     }
   if (width_units % 2 == 0)
     {
-      draw_rectangle (renderer, &total, PANGO_RENDER_PART_UNDERLINE, /* C */
+      draw_rectangle (renderer, &total, part, /* C */
                       HEIGHT_SQUARES * 2 - 2, - (HEIGHT_SQUARES * 2 - 2),
                       1,                      HEIGHT_SQUARES * 2 - 2);
     }
 }
 
 /**
+ * pango_renderer_draw_line:
+ * @renderer: a `PangoRenderer`
+ * @part: type of object this rectangle is part of
+ * @style: the line style
+ * @x: X position at which to draw rectangle, in user space coordinates
+ *   in Pango units
+ * @y: Y position at which to draw rectangle, in user space coordinates
+ *   in Pango units
+ * @width: width of rectangle in Pango units
+ * @height: height of rectangle in Pango units
+ *
+ * Draw a line that approximately covers the given rectangle
+ * in the given style.
+
+ * Since: 1.52
+ */
+void
+pango_renderer_draw_line (PangoRenderer  *renderer,
+                          PangoRenderPart part,
+                          PangoLineStyle  style,
+                          int             x,
+                          int             y,
+                          int             width,
+                          int             height)
+{
+  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
+  g_return_if_fail (renderer->active_count > 0);
+
+  PANGO_RENDERER_GET_CLASS (renderer)->draw_line (renderer, part, style, x, y, width, height);
+}
+
+static void
+pango_renderer_default_draw_line (PangoRenderer  *renderer,
+                                  PangoRenderPart part,
+                                  PangoLineStyle  style,
+                                  int             x,
+                                  int             y,
+                                  int             width,
+                                  int             height)
+{
+  switch (style)
+    {
+    /* FIXME implement these: */
+    case PANGO_LINE_STYLE_DASHED:
+    case PANGO_LINE_STYLE_DOTTED:
+    case PANGO_LINE_STYLE_SINGLE:
+      pango_renderer_draw_rectangle (renderer, part, x, y, width, height);
+      break;
+
+    case PANGO_LINE_STYLE_DOUBLE:
+      pango_renderer_draw_rectangle (renderer, part, x, y, width, height / 3);
+      pango_renderer_draw_rectangle (renderer, part, x, y + height * 2 / 3, width, height / 3);
+      break;
+
+    case PANGO_LINE_STYLE_WAVY:
+      draw_wavy_line (renderer, part, x, y, width, height);
+      break;
+
+    case PANGO_LINE_STYLE_NONE:
+    default:
+      break;
+    }
+}
+
+/**
  * pango_renderer_draw_trapezoid:
  * @renderer: a `PangoRenderer`
  * @part: type of object this trapezoid is part of
diff --git a/pango/pango-renderer.h b/pango/pango-renderer.h
index 2151a243..ae0b23ed 100644
--- a/pango/pango-renderer.h
+++ b/pango/pango-renderer.h
@@ -97,7 +97,6 @@ struct _PangoRenderer
  * PangoRendererClass:
  * @draw_glyphs: draws a `PangoGlyphString`
  * @draw_rectangle: draws a rectangle
- * @draw_error_underline: draws a squiggly line that approximately
  * covers the given rectangle in the style of an underline used to
  * indicate a spelling error.
  * @draw_trapezoid: draws a trapezoidal filled area
@@ -115,7 +114,7 @@ struct _PangoRenderer
  * and have default implementations:
  * - draw_glyphs
  * - draw_rectangle
- * - draw_error_underline
+ * - draw_line
  * - draw_glyph_item
  *
  * The following vfuncs take device space coordinates as doubles
@@ -144,7 +143,9 @@ struct _PangoRendererClass
                                 int               y,
                                 int               width,
                                 int               height);
-  void (*draw_error_underline) (PangoRenderer    *renderer,
+  void (*draw_line)            (PangoRenderer    *renderer,
+                                PangoRenderPart   part,
+                                PangoLineStyle    style,
                                 int               x,
                                 int               y,
                                 int               width,
@@ -219,12 +220,6 @@ void pango_renderer_draw_rectangle       (PangoRenderer    *renderer,
                                           int               width,
                                           int               height);
 PANGO_AVAILABLE_IN_1_8
-void pango_renderer_draw_error_underline (PangoRenderer    *renderer,
-                                          int               x,
-                                          int               y,
-                                          int               width,
-                                          int               height);
-PANGO_AVAILABLE_IN_1_8
 void pango_renderer_draw_trapezoid       (PangoRenderer    *renderer,
                                           PangoRenderPart   part,
                                           double            y1_,
@@ -239,6 +234,14 @@ void pango_renderer_draw_glyph           (PangoRenderer    *renderer,
                                           PangoGlyph        glyph,
                                           double            x,
                                           double            y);
+PANGO_AVAILABLE_IN_1_52
+void pango_renderer_draw_line            (PangoRenderer    *renderer,
+                                          PangoRenderPart   part,
+                                          PangoLineStyle    style,
+                                          int               x,
+                                          int               y,
+                                          int               width,
+                                          int               height);
 
 PANGO_AVAILABLE_IN_1_8
 void pango_renderer_activate             (PangoRenderer    *renderer);
diff --git a/pango/pangocairo-render.c b/pango/pangocairo-render.c
index 688137dd..de38489a 100644
--- a/pango/pangocairo-render.c
+++ b/pango/pangocairo-render.c
@@ -613,7 +613,6 @@ pango_cairo_renderer_draw_rectangle (PangoRenderer     *renderer,
   if (!crenderer->do_path)
     {
       cairo_save (crenderer->cr);
-
       set_color (crenderer, part);
     }
 
@@ -625,7 +624,6 @@ pango_cairo_renderer_draw_rectangle (PangoRenderer     *renderer,
   if (!crenderer->do_path)
     {
       cairo_fill (crenderer->cr);
-
       cairo_restore (crenderer->cr);
     }
 }
@@ -743,35 +741,88 @@ draw_error_underline (cairo_t *cr,
 }
 
 static void
-pango_cairo_renderer_draw_error_underline (PangoRenderer *renderer,
-					   int            x,
-					   int            y,
-					   int            width,
-					   int            height)
+pango_cairo_do_line (cairo_t        *cr,
+                     PangoLineStyle  style,
+                     double          x,
+                     double          y,
+                     double          width,
+                     double          height,
+                     gboolean        do_path)
 {
-  PangoCairoRenderer *crenderer = (PangoCairoRenderer *) (renderer);
-  cairo_t *cr = crenderer->cr;
+  if (!do_path)
+    cairo_new_path (cr);
 
-  if (!crenderer->do_path)
+  switch (style)
     {
+    case PANGO_LINE_STYLE_DOTTED:
+    case PANGO_LINE_STYLE_DASHED:
+      /* FIXME: make this work for paths */
       cairo_save (cr);
+      cairo_set_line_width (cr, height);
+      if (style == PANGO_LINE_STYLE_DOTTED)
+        {
+          cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+          cairo_set_dash (cr, (const double []){ 0., 1.5 * height}, 2, 0.);
+        }
+      else
+        {
+          cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
+          cairo_set_dash (cr, (const double []){ 3. * height, 2 * height}, 2, 0.);
+        }
+      cairo_move_to (cr, x, y + height / 2);
+      cairo_rel_line_to (cr, width, 0.);
+      cairo_stroke (cr);
+      cairo_restore (cr);
+      break;
+
+    case PANGO_LINE_STYLE_SINGLE:
+      cairo_rectangle (cr, x, y, width, height);
+      break;
+
+    case PANGO_LINE_STYLE_DOUBLE:
+      cairo_rectangle (cr, x, y, width, height / 3);
+      cairo_rectangle (cr, x, y + height * 2 / 3, width, height / 3);
+      break;
 
-      set_color (crenderer, PANGO_RENDER_PART_UNDERLINE);
+    case PANGO_LINE_STYLE_WAVY:
+      draw_error_underline (cr, x, y, width, height);
+      break;
 
-      cairo_new_path (cr);
+    case PANGO_LINE_STYLE_NONE:
+    default:
+      break;
     }
 
-  draw_error_underline (cr,
-			crenderer->x_offset + (double)x / PANGO_SCALE,
-			crenderer->y_offset + (double)y / PANGO_SCALE,
-			(double)width / PANGO_SCALE, (double)height / PANGO_SCALE);
+  if (!do_path)
+    cairo_fill (cr);
+}
+
+static void
+pango_cairo_renderer_draw_line (PangoRenderer  *renderer,
+                                PangoRenderPart part,
+                                PangoLineStyle  style,
+                                int             x,
+                                int             y,
+                                int             width,
+                                int             height)
+{
+  PangoCairoRenderer *crenderer = (PangoCairoRenderer *) (renderer);
+  cairo_t *cr = crenderer->cr;
 
   if (!crenderer->do_path)
     {
-      cairo_fill (cr);
-
-      cairo_restore (cr);
+      cairo_save (cr);
+      set_color (crenderer, part);
     }
+
+  pango_cairo_do_line (cr, style,
+                       crenderer->x_offset + (double)x / PANGO_SCALE,
+                       crenderer->y_offset + (double)y / PANGO_SCALE,
+                       (double)width / PANGO_SCALE, (double)height / PANGO_SCALE,
+                       crenderer->do_path);
+
+  if (!crenderer->do_path)
+    cairo_restore (cr);
 }
 
 static void
@@ -788,7 +839,7 @@ pango_cairo_renderer_class_init (PangoCairoRendererClass *klass)
   renderer_class->draw_glyph_item = pango_cairo_renderer_draw_glyph_item;
   renderer_class->draw_rectangle = pango_cairo_renderer_draw_rectangle;
   renderer_class->draw_trapezoid = pango_cairo_renderer_draw_trapezoid;
-  renderer_class->draw_error_underline = pango_cairo_renderer_draw_error_underline;
+  renderer_class->draw_line = pango_cairo_renderer_draw_line;
 }
 
 static PangoCairoRenderer *cached_renderer = NULL; /* MT-safe */
@@ -976,30 +1027,6 @@ _pango_cairo_do_layout (cairo_t     *cr,
   release_renderer (crenderer);
 }
 
-static void
-_pango_cairo_do_error_underline (cairo_t *cr,
-				 double   x,
-				 double   y,
-				 double   width,
-				 double   height,
-				 gboolean do_path)
-{
-  /* We don't use a renderer here, for a simple reason:
-   * the only renderer we can get is the default renderer, that
-   * is all implemented here, so we shortcircuit and make our
-   * life way easier.
-   */
-
-  if (!do_path)
-    cairo_new_path (cr);
-
-  draw_error_underline (cr, x, y, width, height);
-
-  if (!do_path)
-    cairo_fill (cr);
-}
-
-
 /* public wrapper of above to show or append path */
 
 
@@ -1105,34 +1132,31 @@ pango_cairo_show_layout (cairo_t     *cr,
 }
 
 /**
- * pango_cairo_show_error_underline:
+ * pango_cairo_show_line:
  * @cr: a Cairo context
+ * @style: the line style
  * @x: The X coordinate of one corner of the rectangle
  * @y: The Y coordinate of one corner of the rectangle
  * @width: Non-negative width of the rectangle
  * @height: Non-negative height of the rectangle
  *
- * Draw a squiggly line in the specified cairo context that approximately
- * covers the given rectangle in the style of an underline used to indicate a
- * spelling error.
- *
- * The width of the underline is rounded to an integer
- * number of up/down segments and the resulting rectangle is centered in the
- * original rectangle.
+ * Draw a line in the specified cairo context that approximately
+ * covers the given rectangle in the given style.
  *
- * Since: 1.14
+ * Since: 1.52
  */
 void
-pango_cairo_show_error_underline (cairo_t *cr,
-				  double  x,
-				  double  y,
-				  double  width,
-				  double  height)
+pango_cairo_show_line (cairo_t        *cr,
+                       PangoLineStyle  style,
+                       double          x,
+                       double          y,
+                       double          width,
+                       double          height)
 {
   g_return_if_fail (cr != NULL);
   g_return_if_fail ((width >= 0) && (height >= 0));
 
-  _pango_cairo_do_error_underline (cr, x, y, width, height, FALSE);
+  pango_cairo_do_line (cr, style, x, y, width, height, FALSE);
 }
 
 /**
@@ -1171,7 +1195,7 @@ pango_cairo_glyph_string_path (cairo_t          *cr,
  * The origin of the glyphs (the left edge of the line) will be
  * at the current point of the cairo context.
  *
- * Since: 1.10
+ * Since: 1.52
  */
 void
 pango_cairo_layout_line_path (cairo_t          *cr,
@@ -1207,31 +1231,27 @@ pango_cairo_layout_path (cairo_t     *cr,
 }
 
 /**
- * pango_cairo_error_underline_path:
+ * pango_cairo_line_path:
  * @cr: a Cairo context
+ * @style: the line style
  * @x: The X coordinate of one corner of the rectangle
  * @y: The Y coordinate of one corner of the rectangle
  * @width: Non-negative width of the rectangle
  * @height: Non-negative height of the rectangle
  *
- * Add a squiggly line to the current path in the specified cairo context that
- * approximately covers the given rectangle in the style of an underline used
- * to indicate a spelling error.
- *
- * The width of the underline is rounded to an integer number of up/down
- * segments and the resulting rectangle is centered in the original rectangle.
- *
- * Since: 1.14
+ * Add a line to the current path in the specified cairo context that
+ * approximately covers the given rectangle in the given style.
  */
 void
-pango_cairo_error_underline_path (cairo_t *cr,
-				  double   x,
-				  double   y,
-				  double   width,
-				  double   height)
+pango_cairo_line_path (cairo_t        *cr,
+                       PangoLineStyle  style,
+                       double          x,
+                       double          y,
+                       double          width,
+                       double          height)
 {
   g_return_if_fail (cr != NULL);
   g_return_if_fail ((width >= 0) && (height >= 0));
 
-  _pango_cairo_do_error_underline (cr, x, y, width, height, TRUE);
+  pango_cairo_do_line (cr, style, x, y, width, height, TRUE);
 }
diff --git a/pango/pangocairo.h b/pango/pangocairo.h
index f96ae1f4..ac43d680 100644
--- a/pango/pangocairo.h
+++ b/pango/pangocairo.h
@@ -159,12 +159,13 @@ PANGO_AVAILABLE_IN_1_10
 void pango_cairo_show_layout       (cairo_t          *cr,
 				    PangoLayout      *layout);
 
-PANGO_AVAILABLE_IN_1_14
-void pango_cairo_show_error_underline (cairo_t       *cr,
-				       double         x,
-				       double         y,
-				       double         width,
-				       double         height);
+PANGO_AVAILABLE_IN_1_52
+void pango_cairo_show_line         (cairo_t          *cr,
+                                    PangoLineStyle    style,
+                                    double            x,
+                                    double            y,
+                                    double            width,
+                                    double            height);
 
 /*
  * Rendering to a path
@@ -180,12 +181,13 @@ PANGO_AVAILABLE_IN_1_10
 void pango_cairo_layout_path       (cairo_t          *cr,
 				    PangoLayout      *layout);
 
-PANGO_AVAILABLE_IN_1_14
-void pango_cairo_error_underline_path (cairo_t       *cr,
-				       double         x,
-				       double         y,
-				       double         width,
-				       double         height);
+PANGO_AVAILABLE_IN_1_52
+void pango_cairo_line_path         (cairo_t          *cr,
+                                    PangoLineStyle    style,
+                                    double            x,
+                                    double            y,
+                                    double            width,
+                                    double            height);
 
 G_END_DECLS